State Services Commissioner Mark Prebble will investigate claims that leading public servants have been involved in "blatant politicking".
The National Party is furious that little more than a week before the vote, a letter and brochure have been sent to parents and schools detailing the positive aspects of the secondary
school exam system.
Bill English, National's education spokesman, said a mass mailout by civil servants was "blatant politicking by the civil service".
However, Education Minister Trevor Mallard dismissed the claims as ludicrous. The communications campaign was devised before an election date was set and was identified as urgently needed in an independent report, he said.
The National Certificate of Educational Achievement has been in the spotlight since January when extreme variation in scholarship results emerged. An independent report by the State Services Commission found the Qualifications Authority's unstable leadership and poor communication helped to create a lack of consistency in marks.
The exams have been one of the most controversial issues of the year and a key election concern.
The letter sent out promises of no repeat of the Scholarship mess of last year and says the system is designed to help all students achieve to the best of their ability.
"A cohesive qualifications system, which is fair and acknowledges what students can do, will benefit them as individuals and the country as a whole."
It is signed by Karen Sewell, NZQA acting chief executive, and Howard Fancy, Secretary of Education.
Mr English said: "In the heat of the election campaign, the Ministry of Education and NZQA have taken sides with this so-called public education campaign funded by the taxpayer."
Neither the letter nor leaflet mention political parties or the election, concentrating on a description of the NCEA system. However, they are positive about changes made and forthcoming exams.
Mr English said the letter was a breach of State Services Commission guidelines that communications campaigns which could be seen as party political should not happen.
